Machines such as vehicles, either self-propelled or pushed or pulled, often include wheels for facilitating travel across terrain. Such wheels often include a tire to protect a rim or hub of the wheel, provide cushioning for improved comfort or protection of passengers or cargo, and provide enhanced traction via a tread of the tire. Pneumatic tires are an example of such tires. Pneumatic tires include an enclosed cavity for retaining pressurized air, with the enclosed cavity being formed by either a separate annular tube or by a sealed coupling between the tire and a rim of the hub. By virtue of the pressurized air, the tire provides cushioning and shock absorption as the wheel rolls across terrain.
Pneumatic tires, however, may suffer from a number of possible drawbacks. For example, pneumatic tires may deflate due to punctures or air leaks, rendering them unsuitable for use until they are repaired or replaced. In addition, pneumatic tires may be relatively complex due to separate tubes or complex configurations for providing a sealed coupling between the tire and the rim. In addition to these drawbacks, pneumatic tires may suffer from a number of economic drawbacks. For example, due to the relatively complex nature of pneumatic tires, manufacturing facilities for pneumatic tires may be prohibitively costly, requiring a large capital investment. Moreover, pneumatic tires formed from natural rubber may be susceptible to dramatic variability in production costs due to inconsistent availability of natural rubber.
Non-pneumatic tires, such as solid tires or tires not retaining pressurized air, may provide an alternative to pneumatic tires. Non-pneumatic tires may be relatively less complex than pneumatic tires because they do not retain air under pressure. However, non-pneumatic tires may suffer from a number of possible drawbacks. For example, non-pneumatic tires may be relatively heavy and may not be able to provide a desired level of cushioning and support. In addition, it may be relatively costly to produce non-pneumatic tires. For example, molds and associated tooling for making non-pneumatic tires may be relatively costly, particularly for relatively large non-pneumatic tires. In addition, it may be difficult to mold larger sizes of non-pneumatic tires due, for example, to uneven temperatures in the molding material during molding and cooling, and/or difficulties in providing consistent material properties for large amounts of molding material. In addition, it may be difficult to mold non-pneumatic tires having relatively complex designs, thereby limiting design options. This may prevent molded, non-pneumatic tires from achieving desired performance characteristics, such as a desired combination of the level of cushioning and support.
An example of a method of making solid tires for vehicles is disclosed in U.S. Pat. No. 1,806,857 to Liebau (“the '857 patent”). In particular, the '857 patent discloses a method of making solid tires including forming a strip of rubber and folding the strip of rubber so as to provide a plurality of laminations. The folds are pressed together to form a slab having cross-wise extending laminations. The method includes securing the slab to an annular rim with the laminations extending transversely across the circumference of the rim and radially outward from the point of contact with the rim.
Although the method of forming a solid tire disclosed in the '857 patent provides an alternative to molding tires, it may suffer from a number of drawbacks associated with solid tires. For example, the method disclosed in the '857 patent may not be able to form tires having relatively complex designs, for example, to achieve desired characteristics of the finished tire.
The non-pneumatic tire and methods disclosed herein may be directed to mitigating or overcoming one or more of the possible drawbacks set forth above.